Returns a reference to a sorted, unique list of phones covered by the topology (these phones will be positive integers, and usually contiguous and starting from one but the toolkit doesn't assume they are contiguous). More...

Private Attributes

Detailed Description

A class for storing topology information for phones.

See HMM topology and transition modeling for context. This object is sometimes accessed in a file by itself, but more often as a class member of the Transition class (this is for convenience to reduce the number of files programs have to access).

Returns a reference to a sorted, unique list of phones covered by the topology (these phones will be positive integers, and usually contiguous and starting from one but the toolkit doesn't assume they are contiguous).

the pdf-class on the self-loops and forward transitions of all states are identical. [note: in HMMs, the densities are associated with the states.] We have extended this to support 'non-hmm-like' topologies (where those pdf-classes are different), in order to make for more compact decoding graphs in our so-called 'chain models' (AKA lattice-free MMI), where we use 1-state topologies that have different pdf-classes for the self-loop and the forward transition. Note that we always use the 'reorder=true' option so the 'forward transition' actually comes before the self-loop.